Sensor steering for multi-directional long-range perception

ABSTRACT

The present disclosure relates to systems, vehicles, and methods for adjusting a pointing direction and/or a scanning region of a lidar. An example method includes determining a plurality of points of interest within an environment of a vehicle. The method also includes assigning, to each point of interest of the plurality of points of interest, a respective priority score. The method additionally includes partitioning at least a portion of the environment of the vehicle into a plurality of sectors. Each sector of the plurality of sectors includes at least one point of interest. For each sector of the plurality of sectors, the method includes adjusting a scanning region of a lidar unit based on the respective sector and causing the lidar unit to scan the respective sector.

BACKGROUND

Active sensors include devices that emit energy, which can reflect offenvironmental surroundings and can be measured upon return to thedevice. Active sensors include radar and lidar, among others. Suchactive sensors may be utilized in areas such as autonomous orsemi-autonomous vehicles, robotics, mapping, and security applications.

SUMMARY

The present disclosure relates to systems, vehicles, and methods thatinvolve adjustment of a steerable lidar unit based on points of interestwithin an environment.

In a first aspect, a system is provided. The system includes a plannerunit having a planner controller operable to carry out operations. Theoperations include determining a plurality of points of interest withinan environment of the system and assigning, to each point of interest ofthe plurality of points of interest, a respective priority score. Thesystem also includes a perception unit with a perception controlleroperable to carry out operations. The operations include partitioning atleast a portion of the environment of the system into a plurality ofsectors. Each sector of the plurality of sectors includes at least onepoint of interest. The system also includes a lidar unit operable toadjust a scanning region to correspond with a respective sector of theplurality of sectors.

In a second aspect, a vehicle is provided. The vehicle includes aplanner unit with a planner controller operable to carry out operations.The operations include determining a plurality of points of interestwithin an environment of the vehicle and assigning, to each point ofinterest of the plurality of points of interest, a respective priorityscore. The vehicle also includes a perception unit that has a perceptioncontroller operable to carry out operations. The operations includepartitioning at least a portion of the environment of the vehicle into aplurality of sectors. Each sector of the plurality of sectors includesat least one point of interest. The vehicle also includes a lidar unitoperable to adjust a scanning region to correspond with a respectivesector of the plurality of sectors.

In a third aspect, a method is provided. The method includes determininga plurality of points of interest within an environment of a vehicle andassigning, to each point of interest of the plurality of points ofinterest, a respective priority score. The method also includespartitioning at least a portion of the environment of the vehicle into aplurality of sectors. Each sector of the plurality of sectors includesat least one point of interest. The method includes, for each sector ofthe plurality of sectors, adjusting a scanning region of a lidar unitcorresponding with the respective sector. The method also includes, foreach sector of the plurality of sectors, causing the lidar unit to scanthe respective sector.

Other aspects, embodiments, and implementations will become apparent tothose of ordinary skill in the art by reading the following detaileddescription, with reference where appropriate to the accompanyingdrawings.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 illustrates a system, according to an example embodiment.

FIG. 2 illustrates various operations involving the system of FIG. 1 ,according to an example embodiment.

FIG. 3A illustrates a scenario involving the system of FIG. 1 ,according to an example embodiment.

FIG. 3B illustrates a scenario involving the system of FIG. 1 ,according to an example embodiment.

FIG. 3C illustrates a scenario involving the system of FIG. 1 ,according to an example embodiment.

FIG. 3D illustrates a scenario involving the system of FIG. 1 ,according to an example embodiment.

FIG. 3E illustrates a scenario involving the system of FIG. 1 ,according to an example embodiment.

FIG. 3F illustrates a scenario involving the system of FIG. 1 ,according to an example embodiment.

FIG. 4A illustrates a scenario involving the system of FIG. 1 ,according to an example embodiment.

FIG. 4B illustrates a scenario involving the system of FIG. 1 ,according to an example embodiment.

FIG. 4C illustrates a scenario involving the system of FIG. 1 ,according to an example embodiment.

FIG. 4D illustrates a scenario involving the system of FIG. 1 ,according to an example embodiment.

FIG. 4E illustrates a scenario involving the system of FIG. 1 ,according to an example embodiment.

FIG. 5A illustrates a vehicle, according to an example embodiment.

FIG. 5B illustrates a vehicle, according to an example embodiment.

FIG. 5C illustrates a vehicle, according to an example embodiment.

FIG. 5D illustrates a vehicle, according to an example embodiment.

FIG. 5E illustrates a vehicle, according to an example embodiment.

FIG. 6 illustrates a method, according to an example embodiment.

DETAILED DESCRIPTION

Example methods, devices, and systems are described herein. It should beunderstood that the words “example” and “exemplary” are used herein tomean “serving as an example, instance, or illustration.” Any embodimentor feature described herein as being an “example” or “exemplary” is notnecessarily to be construed as preferred or advantageous over otherembodiments or features. Other embodiments can be utilized, and otherchanges can be made, without departing from the scope of the subjectmatter presented herein.

Thus, the example embodiments described herein are not meant to belimiting. Aspects of the present disclosure, as generally describedherein, and illustrated in the figures, can be arranged, substituted,combined, separated, and designed in a wide variety of differentconfigurations, all of which are contemplated herein.

Further, unless context suggests otherwise, the features illustrated ineach of the figures may be used in combination with one another. Thus,the figures should be generally viewed as component aspects of one ormore overall embodiments, with the understanding that not allillustrated features are necessary for each embodiment.

I. Overview

Systems and methods described in various embodiments herein relate tolong-range perception using a steerable light detection and ranging(lidar) device that has a limited angular field of view for a givenposition (e.g., a given azimuthal position). Such systems and methodscould be utilized in semi- or fully-autonomous vehicles, such as withself-driving cars and trucks. In such scenarios, the steerable lidarpoints in one direction at any particular time. However, vehicles thatutilize trajectory and/or route planning may benefit from long rangevisibility in multiple directions at once, or within a brief period oftime (e.g., within 3 seconds or less). For example, when making a leftturn onto a major road, it may be beneficial for a vehicle to senseoncoming traffic at long range both from the left and from the right,and possibly also from straight ahead.

In some embodiments, a method for obtaining information about severalregions of interest within a short period of time could be carried outas follows:

1. A planner unit creates a list of points of interest within anenvironment of a sensing vehicle. Each point of interest describes asingle location or region in space to be scanned in order to detect, forexample, other vehicles, pedestrians, or other moving or non-movingobjects. In some embodiments, each point could be assigned a priorityscore. The priority score for each point could correspond roughly to aninverse of the amount of time it would take for a moving object (e.g.,another vehicle) at that point following the road to intersect with atrajectory of the sensing vehicle. As an example, systems and methodsdescribed herein could take into account an actual or predicted (e.g.,typical average or maximum) speed of other vehicles. As an example,present systems and methods could have information about posted speedlimits and/or average speeds of traffic on nearby roadways. Additionallyor alternatively, present system and methods could receive informationabout current or future weather or road conditions. In such a scenario,the less time the sensing vehicle will have to react to a moving objectapproaching from the given point of interest, the higher the priorityscore. That is, a first point of interest 100 meters away along a foggyroadway with a posted speed limit of 60 miles per hour may be assigned ahigher priority score than that of a second point of interest 100 metersaway along a clear roadway with a posted speed limit of 30 miles perhour. In other terms, higher priority scores may be assigned to pointsof interest corresponding to scenarios where an amount of reaction timeor collision avoidance time is lower, a risk of a collision is higher, atraffic density is higher, etc.

2. A perception unit collects all of these points of interest (andcorresponding priority scores) and partitions or divides at least aportion of the environment into sectors centered at the self-drivingcar's location. Each sector may have an azimuthal angular width thatcorresponds to the angular field of view of the lidar (e.g., between5-15 degrees in azimuth). The algorithm that does this grouping maycollect or aggregate as many points as possible within each sector, andmay seek to maximize overlap between adjacent sectors. For example, ifthe points of interest cannot fit into a single 8 degree sector, butcould fit into a single 12 degree sector, the perception unit may createtwo different 8 degree sectors that overlap in the center 4 degrees. Insuch scenarios, some points may be located within both sectors and willtherefore be detected more frequently. In some embodiments, the groupingalgorithm that collects or aggregates points of interest into sectorscould include a clustering or aggregation algorithm such as a K-meansalgorithm (e.g., Lloyd's algorithm), affinity propagation clusteringalgorithm, or another type of algorithm that utilizes the physicaldistance between points of interest and/or the vehicleposition/orientation to partition the environment into sectors.

3. The perception unit then schedules the lidar to point to differentsectors based on a prediction of how long the lidar would need to scan agiven sector in order for a perception object to be created (e.g., theamount of time needed to scan a given sector before the perception unitwould be expected to recognize a given object). The perception unitallows the lidar to “dwell” on a particular sector for enough time thatan object of interest within the sector will be detected with highlikelihood by the lidar before the lidar is steered to a differentsector. In some embodiments, the lidar may dwell for about 0.75 secondson each sector. Other dwell times (e.g., between 500 milliseconds and 2seconds) are possible and contemplated. Additionally or alternatively,the amount of time that the lidar may dwell on each sector could bevariable. Furthermore, the dwell time could be dynamically adjustable,based on, for example, weather conditions, time of day, current orhistoric traffic patterns, current lidar system performance, sectorsize/volume, distance to point of interest, availability of backupsensor systems to cover a given point of interest, etc.

The algorithm that schedules the steering ensures that “high priority”sectors (e.g., those containing points with expected trajectoryintersection times less than about six seconds) will be visited, but mayignore sectors with lower priority points if there are too many sectorsto ensure that they can all be visited in a timely fashion. In someembodiments, the scheduling algorithm may include a priority-basedscheduling algorithm. For example, the priority-based schedulingalgorithm could include an earliest deadline first (EDF) or leasttime-to-go dynamic scheduling algorithm. For example, from among aplurality of potential sectors to scan, the scheduling algorithm mayselect the sector with the highest priority (effectively the sector withthe least potential intersection time). Additionally or alternatively,the scheduling algorithm could include a first come first serve (FCFS)scheduling algorithm, a shortest job first (SJF) scheduling algorithm,or a round robin (RR) scheduling algorithm, among other possibilities.

In some embodiments, the described systems and methods could represent away to more safely navigate vehicular situations in which other vehiclesmay be approaching from multiple directions. In particular, the lidarmay move back and forth to point at oncoming traffic from differentdirections. In some implementations, this behavior could emerge from thedescribed method without such “back and forth” motion being specificallyprogrammed.

The perception unit's aggregation of points into sectors may attempt tominimize the total number of sectors that are steered to. In suchscenarios, more time could be spent doing perception on relevantlocations of interest and less time may be spent mechanically drivingthe lidar sensor to a new target area. For example, each time the sensoris moved to a new pointing direction, 0.25 second or more of sensorrepointing time could take up time that could otherwise be spentperceiving the scene.

Based on some lidar hardware and sampling rates, the perception unit may“know” that there is sufficient time to steer between 3 differentsectors before starting to push the limits of what the planner unit canprocess using the lidar alone. However, if movement between more thanthree sectors is needed, too much time might be spent looking away froma given sector for the planner unit to be confident enough that thesector is clear to be able to safely proceed. This situation may betaken into account, with the result that some sectors may be droppedfrom the lidar movement schedule altogether. For example, the twohighest priority sectors may be included at all times. However, if morethan two sectors are required, then the lowest priority sectors could bedropped and only the highest priority sectors may be retained by in thesector schedule. While two or three sectors are described in examplesherein, it will be understood that the perception unit may alternativelyschedule a variable number of sectors (e.g., 3, 5, 15, or more sectors).For example, the perception unit may review a specific set of sectorsand dwell times and determine whether a particular scan plan issufficient or not. Based on the sector review, the perception unit mayschedule additional sectors to visit, or may otherwise adjust the sectorvisit order.

In some cases, even if the lidar does not have enough time to scan eachsector over a given period of time, the overall system may still be ableproceed (e.g., move the vehicle) in many cases because radar or othersensors (e.g., other lidar sensors) can be used to scan the areas thatare not scanned by the lidar.

In various embodiments, the systems and methods described herein couldbe applied to lidars with or without affecting their steering (e.g.,physical orientation). For example, adjusting a scanning region of thelidar unit could include a redistribution of light pulse power to arespective sector. In such scenarios, sectors having higher priority maybe illuminated, while the lower priority sectors could be dropped insome cases. In other words, the systems and methods herein could beapplied to other ways to dynamically refocus, redirect, and/orreprioritize lidar regions of interest, including dynamic powermodulation, dynamically adjustable focal distance/depth of field, amongother possibilities.

II. Example Systems

FIG. 1 illustrates a system 100, according to an example embodiment. Thesystem 100 includes a planner unit 110, a perception unit 120, and alidar unit 130.

The planner unit 110 includes a planner controller 112, which mayinclude a planner processor 114 that executes program instructionsstored in a planner memory 116. As such, the planner controller 112could be operable to carry out planner operations. The planneroperations include determining a plurality of points of interest 119within an environment 10 of the system. In some embodiments, the pointsof interest 119 could correspond to locations from which one or moreother vehicles 12 are likely to approach the system 100. In otherscenarios, the points of interest 119 could correspond to locations thatmay be associated with the potential or actual presence of pedestrians,motorcyclists, bicyclists, or other objects.

The planner operations also include assigning, to each point of interestof the plurality of points of interest, a respective priority score 117.

In some embodiments, the planner operations of the planner controller112 may additionally include determining, for each point of interest119, a respective intersection time 115. The respective intersectiontime 115 is based on when another vehicle 12 approaching from therespective point of interest 119 is predicted to intersect a currenttrajectory or a potential trajectory of the system 100.

In such scenarios, the respective priority scores 117 could be inverselyproportional to the respective intersection time 115. For example, if agiven point of interest 119 is associated with vehicles that approach ata high rate of speed, the assigned priority score will be higher thanthat of a point of interest 119 substantially the same distance awaythat is associated with vehicles that approach at a lower rate of speed.In such examples, priority scores 117 may be assigned based on otherinformation. For example, priority scores may be assigned based onactual speeds of oncoming vehicles from around the given point ofinterest 119. Additionally or alternatively, priority scores could beassigned based on object information from prior images or point cloudinformation at the same location and/or similar environment scenarios(e.g., similar traffic patterns, roadways, and/or intersection types).

The perception unit 120 includes a perception controller 122, which mayinclude a perception processor 124 that executes program instructionsstored in a perception memory 126. In such scenarios, the perceptioncontroller 122 could be operable to carry out perception operations. Theperception operations include partitioning the environment 10 of thesystem 100 into a plurality of sectors 127. Each sector of the pluralityof sectors 127 includes at least one point of interest 119.

In some embodiments, partitioning the environment 10 of the system 100into the plurality of sectors 127 could be based on the assignedpriority score 117 of at least one point of interest 119. In someembodiments, each sector of the plurality of sectors 127 could include apredetermined azimuth angle range. As an example, the predeterminedazimuth angle range could be between five degrees and fifteen degrees.

In various embodiments, the perception operations of the perceptioncontroller 122 could additionally include determining a visit order 128of the plurality of sectors 127. In such scenarios, determining thevisit order 128 could be based on a variety of different factors. Forexample, the visit order 128 could be determined based on a number ofpoints of interest in a given sector. In such cases, multiple points ofinterest could be grouped into a single sector to more efficiently scanthe particular sector of the environment 10. Additionally oralternatively, the visit order 128 may be determined based on therespective priority scores 115 for the points of interest 119 in a givensector. For example, the visit order 128 could be based on the estimatedor actual intersection time 115. In such scenarios, the visit order 128could be determined based on how fast vehicles are predicted to approachfrom a particular location of roadway.

In other embodiments, the visit order 128 could be determined based onan angular slew rate of the adjustable mount 132 of the lidar unit 130.That is, an amount of time needed to rotate the adjustable mount 132from an initial pointing direction to a desired pointing direction couldbe taken into account when assigning the visit order 128. In suchscenarios, a sector could be ignored or scanned by another sensor incases where the amount of time needed to slew the lidar unit 130 to thedesired scanning region (corresponding to a desired pointing direction)would be greater than a respective predicted intersection time 115 forobjects approaching from the given sector.

Additionally or alternatively, the visit order 128 could be determinedbased on an actual azimuthal angle of respective sectors of theplurality of sectors and/or an azimuthal angle difference betweenrespective sectors of the plurality of sectors. For example, the visitorder 128 could be assigned so as to sweep the pointing direction 136 ofthe lidar unit 130 through multiple sectors (e.g., instead of ditheringbetween short clockwise and counterclockwise azimuthal movements).

The lidar unit 130 includes an adjustable mount 132. The adjustablemount 132 is operable to rotate the lidar unit 130 toward a respectivesector of the plurality of sectors 127.

In some embodiments, the system 100 could include an actuator 134operable to rotate the lidar unit 130 to an azimuthal anglecorresponding to the respective sector of the plurality of sectors 127.

In various embodiments, the lidar unit 130 could also include atransmitter 140 having at least one light-emitter device 142. The lidarunit 130 may also include a receiver 144 having at least onelight-detector device 146. Additionally or alternatively, the lidar unit130 may include a lidar controller 150, which may include a lidarprocessor 152 that executes program instructions stored in a lidarmemory 154.

The lidar controller 150 could be operable to carry out certain lidaroperations. For example, the lidar operations could include scanningeach respective sector of the plurality of sectors 127 by emitting atleast one light pulse into the respective sector.

In some embodiments, the lidar operations may also include receiving atleast one reflected light pulse from the environment 10.

In such scenarios, the lidar operations could include determining, basedon an emission time of the at least one light pulse, a time of flight ofthe reflected light pulse. Based on the determined time of flight, thelidar operations could include determining a distance to an object(e.g., other vehicles 12) in the respective sector based on the time offlight.

FIG. 2 is a “swimlane”-type diagram that illustrates various operations200 involving elements of system 100 of FIG. 1 , according to an exampleembodiment. While the various operations 200 or blocks are illustratedas being carried out by specific elements of the system 100 (e.g.,planner unit 110, perception unit 120, lidar unit 130, or othercomputing devices), it will be understood that some operations or blockscould be carried out by other elements of system 100. Additionally, itwill be understood that, in some embodiments, the planner unit 110, theperception unit 120, and/or the lidar unit 130 could be physicallyand/or communicatively combined into one or more units.

Operation 210 includes the planner unit 110 determining a plurality ofpoints of interest within the environment 10 of the system 100.

Operation 212 includes the planner unit 110 determining an intersectiontime from each point of interest.

Operation 214 includes the planner unit 110 assigning, based on at leastthe respective intersection time from operation 212, a respectivepriority score to each point of interest.

In example embodiments, operation 216 could include transmittinginformation indicative of the points of interest, intersection times,and/or priority scores to the perception unit 120. Additionally oralternatively, operation 218 could include repeating operations 210,212, and 214 according to a periodic or aperiodic planner schedule.

Operation 220 includes the perception unit 120 partitioning theenvironment into a plurality of sectors.

Operation 222 includes the perception unit 120 determining a visit orderof the sectors based on the priority score of respective points ofinterest within the given sector.

Operation 224 includes the perception unit 120 transmitting informationindicative of the visit order and/or the sectors to the lidar unit 130.

Operation 228 includes repeating operations 220 and 222 according to aperiodic or aperiodic perception schedule.

Operation 230 includes the lidar unit 130 rotating to the first visitorder sector. In such scenarios, a rotatable housing could rotate apointing direction of the lidar unit 130 toward an azimuthal directionassociated with the first visit order sector.

Operation 232 includes the lidar unit 130 scanning the first visit ordersector. In some embodiments, scanning a given sector could includeemitting a plurality of light pulses toward various locations within thesector, and receiving a plurality of return pulses. In some embodiments,scanning the given sector could include measuring a time of flightbetween emission of the light pulses and the time at which thecorresponding return pulse is received.

Operation 234 may include rotating the lidar unit 130 in azimuthal angletoward the next sector in visit order.

Operation 236 could include scanning the next sector. Operation 238could include repeating operations 230, 232, 234 and/or 236 according toa period or aperiodic lidar scanning schedule. Operation 240 couldinclude repeating some or all of the various operations 200.

FIG. 3A illustrates a scenario 300 involving the system 100 of FIG. 1 ,according to an example embodiment. As an example, the planner unit 110could generate a list of points of interest (e.g., points of interest306 a, 306 b, and 306 c) within an environment 10 of a vehicle 500. Insuch scenarios, each point of interest 306 a, 306 b, and 306 c couldrelate to a single location or region in space for which the plannerunit 110 seeks further information. For example, points of interest 306a, 306 b, and 306 c could relate to another vehicle, a pedestrian, amoving object, a stationary object, or another type of object.

In some embodiments, each point of interest could be assigned a priorityscore that may correspond roughly to an inverse of the amount of time itwould take for an object, such as another vehicle or another type ofmoving object at that location following a predicted trajectory, tointersect with the trajectory of vehicle 500. For example, point ofinterest 306 a could be assigned a priority score of 10 (e.g.,corresponding to a fast-approaching vehicle), point of interest 306 bcould be assigned a priority of 2 (e.g., corresponding to a slow-movingpedestrian), and point of interest 306 c could be assigned a priorityscore of 6 (e.g., corresponding to another vehicle overtaking from aleft-hand lane).

Subsequently, the perception unit 120 may receive the points of interest(and the corresponding priority scores) and divide or partition at leasta portion of the environment 10 into a plurality of sectors centered atthe location of vehicle 500 (and/or centered at the location of lidarunit 130. In such a scenario, each sector could have an azimuthalangular width that is the same as the angular field of view of the lidar(e.g., between 5-15 degrees in azimuth). In other embodiments, thesectors could have an azimuthal angular width based on size of thepoints of interest and/or an angular extent of several points ofinterest. In such scenarios, the perception unit 120 may attempt toaggregate as many points as possible within each sector, and maximizeoverlap between adjacent sectors, when relevant. For example, if thepoints of interest cannot fit into a single 8 degree sector (e.g., pointof interest 306 c), but could fit into a single 12 degree sector, theperception unit 120 may create two different 8 degree sectors thatoverlap in the center 4 degrees. In such scenarios, some points may belocated within both sectors and will therefore be detected morefrequently. Other ways to partition the environment 10 around thevehicle 500 are contemplated and possible.

In the illustrated scenario 300, the partitioned sectors couldinclude: 1) sector 304 a, which corresponds to point of interest 306 a;2) sector 304 b, which corresponds to point of interest 306 b; and 3)sectors 304 c and 304 d, which correspond to point of interest 306 c.Other portions of the environment 10 could also be partitioned intosectors or could remain unpartitioned.

Although not shown, scenario 300 could include the lidar unit 130scanning sector 304 a (highest priority score), then sectors 304 c and304 d (next highest priority score), followed by sector 304 b (lowestpriority score). It will be understood that while scenario 300 includesthree different points of interest, some scenarios may include greateror lesser numbers of points of interest and corresponding sectors. Thefollowing scenarios illustrate other potential real-world examples.

FIG. 3B illustrates a scenario 320 involving the system 100 of FIG. 1 ,according to an example embodiment. Scenario 320 could be based on anunprotected left hand turn where a vehicle 500 in roadway 321 is waitingat a stop sign 323 with the intention of proceeding along trajectory324. While roadway 336 has a stop sign 337, the other roadways do nothave a stop. Such a scenario could be similar or identical to anintersection with a two-lane highway.

In such an example, three main roadway portions to check are roadway 328(oncoming traffic from the left), roadway 330 (oncoming traffic from theright), and roadway 336 (oncoming traffic from the front). Otherroadways portions (e.g., roadway 334, 332, 326, and 338 are lessimportant because vehicles in those roadway portions are not likely tointersect (e.g., potentially collide) with the vehicle 500 or theintended trajectory 324.

Accordingly, the planner unit 110 may assign three points of interest322 a, 322 b, and 322 c. Furthermore, the planner unit 110 may assignrespective priority scores of 10, 9, and 7, which could be substantiallyinversely proportional to the speed limit or average speed ofhypothetical vehicles approaching vehicle 500 or intended trajectory 324from the respective points of interest. For example, other vehiclesapproaching from points of interest 322 a and 322 b could be travelingat approximately 60 miles per hour, while other vehicles approachingfrom point of interest 322 c may approach at 30 miles per hour.

Although not illustrated, the perception unit 120 could partition theenvironment into three different sectors corresponding to the threedifferent points of interest 322 a, 322 b, and 322 c. In someembodiments, the sector visit order could be assigned based on thepriority score of the respective points of interest in the sector.

FIG. 3C illustrates a scenario 340 involving the system 100 of FIG. 1 ,according to an example embodiment. In such a scenario, the lidar unit130 of system 100 may rotate an adjustable mount in azimuthal angle frominitial sector 342 to sector 344, which includes the point of interest322 a with the highest priority score of 10. Scenario 340 may includethe lidar unit 130 scanning within the sector 344 so as to obtaininformation about potential objects (or absence thereof).

FIG. 3D illustrates a scenario 350 involving the system 100 of FIG. 1 ,according to an example embodiment. In such a scenario, the lidar unit130 of system 100 may rotate or slew an adjustable mount in azimuthalangle from sector 344 to sector 352, which includes the point ofinterest 322 b with the second-highest priority score of 9. Scenario 350may include the lidar unit 130 scanning within the sector 352 so as toobtain information about potential objects (or absence thereof).

FIG. 3E illustrates a scenario 360 involving the system 100 of FIG. 1 ,according to an example embodiment. In such a scenario, the lidar unit130 of system 100 may rotate or slew an adjustable mount in azimuthalangle from sector 352 to sector 362, which includes the point ofinterest 322 c with the lowest priority score of 7. Scenario 360 mayinclude the lidar unit 130 scanning within the sector 362 so as toobtain information about potential objects (or absence thereof).

FIG. 3F illustrates a scenario 370 involving the system 100 of FIG. 1 ,according to an example embodiment. In such a scenario, the lidar unit130 of system 100 may rotate or slew an adjustable mount in azimuthalangle from sector 362 back to highest-priority sector 344, whichincludes the point of interest 322 a. That is, in some embodiments, thelidar unit 130 may be configured to repeat the same scanning cycle,jumping from one sector to the next, based on priority score and/orsector visit order. Scenario 370 may include the lidar unit 130re-scanning the sector 344 so as to obtain the latest possibleinformation about potential objects (or absence thereof).

FIG. 4A illustrates a scenario 400 involving the system 100 of FIG. 1 ,according to an example embodiment. Scenario 400 could be based on ahighway merging scenario where a vehicle 500 in roadway 402 is mergingonto a highway 404 with the intention of proceeding along trajectory403. In such a scenario, the planner unit 110 could identify point ofinterest 412 a, which could correspond to potential vehicles approachingfrom closest lane 406 and farthest lane 408. The planner unit 110 couldalso identify point of interest 412 b, which may correspond to aslow-moving or stopped vehicle in forward lane 410.

As illustrated, the planner unit 110 could assign priority scores to thepoints of interest based on, for example, the approach speed of vehiclespresent in the given locations among other factors. For example, pointof interest 412 a could be assigned a priority score of 9 while point ofinterest 412 b could be assigned a priority score of 6.

Subsequent to priority score assignment, the perception unit 120 couldpartition the environment into sectors that each include at least onepoint of interest. In scenario 400, point of interest 412 a could belarger than a single sector azimuth angle range. Accordingly, in someexamples, as described below, two sectors may be assigned to a singlepoint of interest.

FIG. 4B illustrates a scenario 420 involving the system 100 of FIG. 1 ,according to an example embodiment. Scenario 420 could include slewingor rotating the lidar unit 130 counterclockwise (when viewed overhead)from an initial sector 422 to sector 424, which may correspond to one ofthe two sectors assigned to highest-priority score point of interest 412a. Once oriented along the desired pointing direction, the lidar unit130 may be configured to scan the sector 424.

FIG. 4C illustrates a scenario 430 involving the system 100 of FIG. 1 ,according to an example embodiment. Scenario 430 could include slewingor rotating the lidar unit 130 clockwise (when viewed overhead) fromsector 424 to sector 432, which may correspond to the second of the twosectors assigned to highest-priority score point of interest 412 a. Onceoriented along the desired pointing direction, the lidar unit 130 may beconfigured to scan the sector 432.

FIG. 4D illustrates a scenario 440 involving the system 100 of FIG. 1 ,according to an example embodiment. Scenario 440 could include slewingor rotating the lidar unit 130 clockwise (when viewed overhead) fromsector 432 to sector 442, which may correspond to the lower-priorityscore point of interest 412 b. Once oriented along the desired pointingdirection, the lidar unit 130 may be configured to scan the sector 442.

FIG. 4E illustrates a scenario 450 involving the system 100 of FIG. 1 ,according to an example embodiment. Scenario 450 could include slewingor rotating the lidar unit 130 counterclockwise (when viewed overhead)from sector 442 to sector 424, which may correspond to the first of twosectors given the highest priority score. Once oriented along thedesired pointing direction, the lidar unit 130 may be configured to scanthe sector 424.

III. Example Vehicles

FIGS. 5A, 5B, 5C, 5D, and 5E illustrate a vehicle 500, according to anexample embodiment. In some embodiments, the vehicle 500 could be asemi- or fully-autonomous vehicle. While FIGS. 5A, 5B, 5C, 5D, and 5Eillustrates vehicle 500 as being an automobile (e.g., a passenger van),it will be understood that vehicle 500 could include another type ofautonomous vehicle, robot, or drone that can navigate within itsenvironment using sensors and other information about its environment.

The vehicle 500 could include a planner unit (e.g., planner unit 110).The planner unit could include a planner controller (e.g., plannercontroller 112) operable to carry out planner operations. The planneroperations could include determining a plurality of points of interestwithin an environment (e.g., environment 10) of the vehicle 500.

The planner operations could include assigning, to each point ofinterest of the plurality of points of interest, a respective priorityscore (e.g., priority score(s) 117).

The vehicle 500 includes a perception unit (e.g., perception unit 120),which may include a perception controller (e.g., perception controller122) operable to carry out perception operations. The perceptionoperations could include partitioning the environment of the vehicle 500into a plurality of sectors (e.g., plurality of sectors 127). Eachsector of the plurality of sectors includes at least one point ofinterest (e.g., points of interest 119).

The vehicle 500 includes a lidar unit (e.g., lidar unit 130). The lidarunit includes an adjustable mount (e.g., adjustable mount 132). Theadjustable mount is operable to rotate the lidar unit toward arespective sector of the plurality of sectors.

Additionally or alternatively, the vehicle 500 may include one or moresensor systems 502, 504, 506, 508, and 510. In some embodiments, sensorsystems 502, 504, 506, 508, and 510 could include system 100 asillustrated and described in relation to FIG. 1 . In other words, thesystems described elsewhere herein could be coupled to the vehicle 500and/or could be utilized in conjunction with various operations of thevehicle 500. As an example, the system 100 could be utilized inself-driving or other types of navigation, planning, perception, and/ormapping operations of the vehicle 500.

While the one or more sensor systems 502, 504, 506, 508, and 510 areillustrated on certain locations on vehicle 500, it will be understoodthat more or fewer sensor systems could be utilized with vehicle 500.Furthermore, the locations of such sensor systems could be adjusted,modified, or otherwise changed as compared to the locations of thesensor systems illustrated in FIGS. 5A, 5B, 5C, 5D, and 5E.

In some embodiments, the one or more sensor systems 502, 504, 506, 508,and 510 could include image sensors. Additionally or alternatively theone or more sensor systems 502, 504, 506, 508, and 510 could includelidar sensors. For example, the lidar sensors could include a pluralityof light-emitter devices arranged over a range of angles with respect toa given plane (e.g., the x-y plane). For example, one or more of thesensor systems 502, 504, 506, 508, and 510 may be configured to rotateabout an axis (e.g., the z-axis) perpendicular to the given plane so asto illuminate an environment around the vehicle 500 with light pulses.Based on detecting various aspects of reflected light pulses (e.g., theelapsed time of flight, polarization, intensity, etc.), informationabout the environment may be determined.

In an example embodiment, sensor systems 502, 504, 506, 508, and 510 maybe configured to provide respective point cloud information that mayrelate to physical objects within the environment of the vehicle 500.While vehicle 500 and sensor systems 502, 504, 506, 508, and 510 areillustrated as including certain features, it will be understood thatother types of sensor systems are contemplated within the scope of thepresent disclosure.

While lidar systems with single light-emitter devices are described andillustrated herein, lidar systems with multiple light-emitter devices(e.g., a light-emitter device with multiple laser bars on a single laserdie) are also contemplated. For example, light pulses emitted by one ormore laser diodes may be controllably directed about an environment ofthe system. The angle of emission of the light pulses may be adjusted bya scanning device such as, for instance, a mechanical scanning mirrorand/or a rotational motor. For example, the scanning devices couldrotate in a reciprocating motion about a given axis and/or rotate abouta vertical axis. In another embodiment, the light-emitter device mayemit light pulses towards a spinning prism mirror, which may cause thelight pulses to be emitted into the environment based on an angle of theprism mirror angle when interacting with each light pulse. Additionallyor alternatively, scanning optics and/or other types ofelectro-opto-mechanical devices are possible to scan the light pulsesabout the environment. While FIGS. 5A-5E illustrate various lidarsensors attached to the vehicle 500, it will be understood that thevehicle 500 could incorporate other types of sensors.

IV. Example Methods

FIG. 6 illustrates a method 600, according to an example embodiment. Itwill be understood that the method 600 may include fewer or more stepsor blocks than those expressly illustrated or otherwise disclosedherein. Furthermore, respective steps or blocks of method 600 may beperformed in any order and each step or block may be performed one ormore times. In some embodiments, some or all of the blocks or steps ofmethod 600 may relate to elements of system 100 and/or vehicle 500 asillustrated and described in relation to FIG. 1 and FIG. 5 ,respectively. Furthermore, some or all of the block or steps of method600 may relate to various operations 200 of the system 100 asillustrated and described in relation to FIG. 2 . Additionally oralternatively, steps or blocks of method 600 may relate to any ofscenarios 300, 320, 340, 350, 360, 370, 400, 420, 430, 440, or 450, asillustrated and described in relation to FIGS. 3A-3F and 4A-4E,respectively.

Block 602 includes determining a plurality of points of interest (e.g.,points of interest 306 a, 306 b, and/or 306 c, etc.) within anenvironment (e.g., environment 10) of a vehicle (e.g., vehicle 500). Insome embodiments, the points of interest could correspond to locationsfrom which one or more other vehicles (e.g., other vehicles 12) arelikely to approach.

Block 604 includes assigning, to each point of interest of the pluralityof points of interest, a respective priority score.

Block 606 includes partitioning at least a portion of the environment ofthe vehicle into a plurality of sectors (e.g., sectors 304 a, 304 b, 304c, and 304 d, etc.). Each sector of the plurality of sectors includes atleast one point of interest.

Block 608 includes, for each sector of the plurality of sectors,adjusting a pointing direction (e.g., pointing direction 136) or ascanning region (e.g., scanning region 137) of a lidar unit (e.g., lidarunit 130) corresponding with the respective sector.

Block 610 includes, for each sector of the plurality of sectors, causingthe lidar unit to scan the respective sector.

In some embodiments, method 600 may include determining, for each pointof interest, a respective intersection time (e.g., intersection times115). The respective intersection time could be based on a future timewhen another (actual or potential) vehicle approaching from therespective point of interest is predicted to intersect a currenttrajectory or a potential trajectory of the vehicle. In such scenarios,the respective priority scores could be substantially inverselyproportional to the respective intersection time.

In some embodiments, partitioning at least a portion of the environmentof the vehicle into the plurality of sectors could be based on theassigned priority score of at least one point of interest.

Furthermore, in various examples, each sector of the plurality ofsectors could include a predetermined azimuth angle range. For example,the predetermined azimuth angle range could be between five degrees andfifteen degrees.

In some embodiments, adjusting the pointing direction of the lidar unitcould include causing an actuator to rotate the lidar unit to a pointingdirection or an azimuthal angle corresponding to the respective sector.

In example embodiments, causing the lidar unit to scan the respectivesector could include emitting at least one light pulse into therespective sector and receiving at least one reflected light pulse fromthe environment. In such scenarios, causing the lidar unit to scan therespective sector could also include determining, based on an emissiontime of the at least one light pulse, a time of flight of the reflectedlight pulse. Additionally, causing the lidar unit to scan the respectivesector may additionally include determining a distance to an object inthe respective sector based on the time of flight.

In some examples, method 600 could additionally include determining avisit order (e.g., visit order 128) of the plurality of sectors. In suchscenarios, determining the visit order could be based on at least oneof: a number of points of interest in a given sector, the respectivepriority scores for the points of interest in a given sector, an angularslew rate of the lidar unit, or an azimuthal angle difference betweenrespective sectors of the plurality of sectors.

In various embodiments, the adjusting and causing steps for each sectorof the plurality of sectors could be performed according to thedetermined visit order.

The particular arrangements shown in the Figures should not be viewed aslimiting. It should be understood that other embodiments may includemore or less of each element shown in a given Figure. Further, some ofthe illustrated elements may be combined or omitted. Yet further, anillustrative embodiment may include elements that are not illustrated inthe Figures.

A step or block that represents a processing of information cancorrespond to circuitry that can be configured to perform the specificlogical functions of a herein-described method or technique.Alternatively or additionally, a step or block that represents aprocessing of information can correspond to a module, a segment, or aportion of program code (including related data). The program code caninclude one or more instructions executable by a processor forimplementing specific logical functions or actions in the method ortechnique. The program code and/or related data can be stored on anytype of computer readable medium such as a storage device including adisk, hard drive, or other storage medium.

The computer readable medium can also include non-transitory computerreadable media such as computer-readable media that store data for shortperiods of time like register memory, processor cache, and random accessmemory (RAM). The computer readable media can also includenon-transitory computer readable media that store program code and/ordata for longer periods of time. Thus, the computer readable media mayinclude secondary or persistent long term storage, like read only memory(ROM), optical or magnetic disks, compact-disc read only memory(CD-ROM), for example. The computer readable media can also be any othervolatile or non-volatile storage systems. A computer readable medium canbe considered a computer readable storage medium, for example, or atangible storage device.

While various examples and embodiments have been disclosed, otherexamples and embodiments will be apparent to those skilled in the art.The various disclosed examples and embodiments are for purposes ofillustration and are not intended to be limiting, with the true scopebeing indicated by the following claims.

What is claimed is:
 1. A method comprising: determining a plurality ofpoints of interest within an environment of a vehicle; assigning, toeach point of interest of the plurality of points of interest, arespective priority score; partitioning at least a portion of theenvironment of the vehicle into a plurality of sectors based on anangular field of view of a lidar unit, wherein each sector of theplurality of sectors includes at least one point of interest;determining a schedule for scanning the plurality of sectors by thelidar unit; for each sector of the plurality of sectors: adjusting ascanning region of a lidar unit corresponding with the respective sectorin accordance with the schedule; and causing the lidar unit to scan therespective sector in accordance with the schedule.
 2. The method ofclaim 1, wherein the points of interest correspond to locations fromwhich one or more other vehicles are likely to approach.
 3. The methodof claim 2, further comprising: determining, for each point of interest,a respective intersection time, wherein the respective intersection timeis based on when another vehicle approaching from the respective pointof interest would be predicted to intersect a current trajectory or apotential trajectory of the vehicle.
 4. The method of claim 3, whereinthe respective priority scores are inversely proportional to therespective intersection time.
 5. The method of claim 1, whereinpartitioning at least the portion of the environment of the vehicle intothe plurality of sectors is based on the assigned priority score of atleast one point of interest.
 6. The method of claim 1, wherein eachsector of the plurality of sectors comprises a predetermined azimuthangle range, wherein the predetermined azimuth angle range correspondsto the angular field of view of the lidar unit.
 7. The method of claim1, wherein adjusting the scanning region of the lidar unit comprisescausing an actuator to rotate the lidar unit to an azimuthal anglecorresponding to the respective sector so as to change a pointingdirection of the lidar unit.
 8. The method of claim 1, wherein causingthe lidar unit to scan the respective sector comprises: emitting atleast one light pulse into the respective sector; receiving at least onereflected light pulse from the environment; and determining, based on anemission time of the at least one light pulse, a time of flight of thereflected light pulse; and determining a distance to an object in therespective sector based on the time of flight.
 9. The method of claim 1,wherein determining the schedule for scanning the plurality of sectorscomprises: determining a visit order of the plurality of sectors,wherein determining the visit order is based on at least one of: anumber of points of interest in a given sector, the respective priorityscores for the points of interest in a given sector, an angular slewrate of the lidar unit, or an azimuthal angle difference betweenrespective sectors of the plurality of sectors.
 10. The method of claim9, wherein the adjusting and causing steps for each sector of theplurality of sectors are performed according to the determined visitorder.
 11. A system comprising: a planner unit comprising a plannercontroller operable to carry out operations, the operations comprising:determining a plurality of points of interest within an environment ofthe system; and assigning, to each point of interest of the plurality ofpoints of interest, a respective priority score; a perception unitcomprising a perception controller operable to carry out operations, theoperations comprising: partitioning at least a portion of theenvironment of the system into a plurality of sectors based on anangular field of view of a lidar unit, wherein each sector of theplurality of sectors includes at least one point of interest; anddetermining a schedule for scanning the plurality of sectors by thelidar unit, wherein the lidar unit is operable to adjust a scanningregion to correspond with a respective sector of the plurality ofsectors in accordance with the schedule.
 12. The system of claim 11,wherein the points of interest correspond to locations from which one ormore other vehicles are likely to approach.
 13. The system of claim 12,wherein the operations of the planner unit further comprise:determining, for each point of interest, a respective intersection time,wherein the respective intersection time is based on when anothervehicle approaching from the respective point of interest is predictedto intersect a current trajectory or a potential trajectory of thesystem.
 14. The system of claim 13, wherein the respective priorityscores are inversely proportional to the respective intersection time.15. The system of claim 11, wherein partitioning at least the portion ofthe environment of the system into the plurality of sectors is based onthe assigned priority score of at least one point of interest.
 16. Thesystem of claim 11, wherein each sector of the plurality of sectorscomprises a predetermined azimuth angle range, wherein the predeterminedazimuth angle range corresponds to the angular field of view of thelidar unit.
 17. The system of claim 11, further comprising an adjustablemount and an actuator operable to rotate the lidar unit to an azimuthalangle corresponding to the respective sector.
 18. The system of claim11, further comprising the lidar unit, wherein the lidar unit comprises:at least one light-emitter device; at least one light-detector device;and a lidar controller operable to carry out operations, the operationscomprising: scanning each respective sector of the plurality of sectorsby: emitting at least one light pulse into the respective sector;receiving at least one reflected light pulse from the environment;determining, based on an emission time of the at least one light pulse,a time of flight of the reflected light pulse; and determining adistance to an object in the respective sector based on the time offlight.
 19. The system of claim 11, wherein determining the schedule forscanning the plurality of sectors comprises: determining a visit orderof the plurality of sectors, wherein determining the visit order isbased on at least one of: a number of points of interest in a givensector, the respective priority scores for the points of interest in agiven sector, an angular slew rate of the lidar unit, or an azimuthalangle difference between respective sectors of the plurality of sectors.20. A vehicle comprising: a lidar unit; a planner unit comprising aplanner controller operable to carry out operations, the operationscomprising: determining a plurality of points of interest within anenvironment of the vehicle; and assigning, to each point of interest ofthe plurality of points of interest, a respective priority score; aperception unit comprising a perception controller operable to carry outoperations, the operations comprising: partitioning at least a portionof the environment of the vehicle into a plurality of sectors based onan angular field of view of the lidar unit, wherein each sector of theplurality of sectors includes at least one point of interest; anddetermining a schedule for scanning the plurality of sectors by thelidar unit, wherein the lidar unit is operable to adjust a scanningregion to correspond with a respective sector of the plurality ofsectors in accordance with the schedule.